01.26.13

Everyone knows that renewable energy in the form of solar and wind has big problems when it comes to providing reliable electricity generation.

Photo-Voltaic (PV), the solar technology being installed at a frantic pace all over the world supported by Feed-In-Tariffs is notoriously variable. Wind is even worse, even when averaged over a large geographic area.

For example, Texas set a new wind energy generation record for the state on Christmas day, 2012 – 8.63 GW for a few hours. The very next day, between noon and 6:00 pm all the wind farms in Texas combined produced less than 0.3 GW.

But there is a source of renewable energy that can be relied upon to produce electricity 24 hours a day, 365 days a year. That is Concentrated Solar Power (CSP) supplemented by molten salt Thermal Energy Storage (TES).

In July, 2011 the Gemasolar CSP plant in Spain produced electricity for 24 continuous hours. And that was no fluke. I recently contacted Torresol Energy, developer of the facility, and got sample production figures for both summer and winter production, shown below;

In the summer time there is enough solar power to maximize the TES so that the plant can run at full capacity 24 hours a day. In the winter the plant can still run at capacity during peak demand times but output is cut back for a few hours at night.

Plants similar to Gemasolar are under construction in the United States today, the largest being the Ivanpah plant in California's Mohave desert.

Is the technology expensive? Yes, significantly more than the cost of PV. But considering that peak demand for electricity occurs just as PV is fading in the late afternoon and evening the cost of CSP is easily justified.